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Error code reference

Samsung Air Conditioner Error Code 703

1st open indoor electrically operated valve error.

Samsung codesSamsung air conditioner codes

1st open indoor electrically operated valve error.

First step from the service manual

Check PCB connection of electrically operated valve wire; check sealing condition; check for external rust, internal breakage/short circuit on coil; reset OU (K3) and re-check.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 703 means on a Samsung air conditioner

Error code 703 on a Samsung air conditioner indicates a fault with the first indoor electrically operated valve (EOV), also commonly referred to as an electronic expansion valve or solenoid-driven refrigerant control valve. This valve is responsible for regulating refrigerant flow into the indoor unit, and when the system's PCB cannot confirm proper operation or electrical continuity through the valve coil, it triggers this fault code to prevent potential system damage or inefficient operation.

The most common sources of this error involve the electrical connection between the indoor unit PCB and the valve coil wiring harness. A loose, corroded, or improperly seated connector at the PCB can interrupt the signal or power delivery needed to drive the valve. Beyond wiring issues, the valve coil itself can fail through an internal short circuit or an open circuit caused by a broken winding, both of which will prevent the PCB from detecting correct coil resistance. External rust on the valve body can also interfere mechanically with valve movement, while physical damage to the coil casing can expose windings to moisture or shorts.

Diagnostic procedure begins with a physical inspection of the EOV wiring harness connection at the indoor PCB, checking for secure seating and absence of corrosion or pin damage. The coil should then be tested for resistance and inspected for external rust or visible damage to the housing. After any corrections are made, the outdoor unit control board (K3) should be reset and the system re-evaluated to confirm the fault has cleared and the valve responds correctly.

Source: manufacturer service documentation.

Common causes of 703

  1. 01

    Loose or faulty PCB wiring connection

    Wiring / connection

    The wire harness connecting the electrically operated valve to the indoor PCB may be loose, corroded, or improperly seated. Inspecting and reseating the connector at the board is the first step in diagnosis.

  2. 02

    Open circuit or broken coil winding

    Part replacement

    An internal break in the valve coil winding creates an open circuit that the PCB cannot drive. This is confirmed by measuring coil resistance and finding an out-of-specification or infinite reading.

  3. 03

    Short circuit within the valve coil

    Part replacement

    A shorted coil winding can cause abnormal current draw and trigger the fault. This is typically identified through resistance testing or visible burn marks on the coil body.

  4. 04

    External rust on the valve body

    Part replacement

    Rust buildup on the exterior of the electrically operated valve can mechanically restrict valve movement, preventing proper operation even if the coil is electrically sound.

  5. 05

    Poor sealing condition at the valve

    Part replacement

    A compromised seal around the valve assembly can allow moisture ingress, leading to corrosion of internal components or electrical shorting of the coil. Visually inspect the valve housing and surrounding seals for any gaps or deterioration.

See the test procedure for each cause

Frequently asked questions about 703

What does 703 mean on a Samsung air conditioner?
Error code 703 on a Samsung air conditioner signals a fault with the first indoor electrically operated valve. This valve controls refrigerant flow into the indoor unit, and the system has detected an electrical or mechanical problem with it. The issue can stem from a loose wiring connection, a failed coil, or physical damage to the valve itself.
Can I fix error code 703 on my Samsung air conditioner myself?
Some basic checks, such as inspecting the valve wiring harness connection at the PCB for looseness or corrosion, can be performed by a knowledgeable DIYer. However, testing coil resistance, identifying internal short circuits, or replacing the valve involves working with refrigerant-side components and electrical systems that are best handled by a qualified HVAC technician. Attempting repairs beyond wiring inspection without proper training is not recommended.
Is it safe to run my Samsung air conditioner while error code 703 is active?
Running the system while this fault is active is not advisable. A malfunctioning electrically operated valve can lead to improper refrigerant flow, which may cause the system to operate inefficiently, freeze up, or sustain compressor damage over time. The unit should be serviced before returning to regular operation.
How much does it cost to repair error code 703 on a Samsung air conditioner?
Repair costs vary depending on the root cause. If the fix is as simple as reseating a loose connector, labor costs may be minimal, typically in the range of $75 to $150 for a service call. If the electrically operated valve coil or the full valve assembly requires replacement, total costs including parts and labor can range from $150 to $400 or more depending on the model and local labor rates.
Will resetting the outdoor unit clear error code 703 on a Samsung air conditioner?
Resetting the outdoor unit control board (K3) is part of the recommended diagnostic procedure and may temporarily clear the code. However, if the underlying issue with the electrically operated valve wiring, coil condition, or valve body has not been resolved, the error will return. A reset alone is not a fix and should only be used to confirm whether a repair was successful.

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